1. Field of the Invention
The present invention relates generally to the field of Radio Frequency Identification (RFID) systems.
2. Background Art
Radio frequency identification (RFID) is a wireless form of identification technology that allows for reading of data from an object bearing an RFID tag. RFID tags are used to identify objects in manufacturing and service environments. An RFID system includes a tag and a reader. The reader is also referred to as an interrogator or receiver. The reader is designed to receive and transmit electromagnetic waves to generate an electromotive field (EMF). The tag, commonly referred to as an RFID tag, has a transponder and either a wound antenna or printed antenna. The tag may be either of an electromagnetic induction type or an electromagnetic coupling type. Both types of tags are designed to communicate with the reader in a non-contact manner.
The antenna of the tag picks up signals from and sends signals to a reader. The reader typically contains a radio frequency (RF) transceiver. If the transceiver is triggered, the reader's transceiver generates an electromotive field (EMF) that is directed towards the RFID tag. The electromotive field is often called an interrogation signal or a carrier signal. In a passive RFID tag system, the electromotive field supplies power to the antenna to generate an activation signal. The activation signal is used to energize the RFID tag's transponder. In response to the activation signal, the RFID tag responds by sending a coded signal back to the RFID reader containing information stored and/or modulated by the transponder. The RFID reader detects the coded signal and the coded signal can be used to convey instructions and other information.
An RFID tag can be either an active tag, a passive tag, or a semi-passive tag. Active tags typically transmit continuously or periodically. Active tags are battery powered. Passive tags transmit in response to an interrogation signal generated by the reader. Semi-passive tags are a hybrid of active tags and passive tags. Semi-passive tags use a battery to run the circuits of the chip, but communicate by drawing power from the electromotive field generated by the reader.
One example of an electronic identification system is described in U.S. Pat. No. 6,847,856. This invention requires multiple RFID tags that are used to determine proper connectivity or alignment between physical components.
There is a need to accurately determine the connectivity and/or the proper assembly of physical components during manufacturing and servicing of the physical components. Additionally, there is a need to interrogate and verify the proper assembly of components in manufacturing systems in a relatively inexpensive and streamlined manner. Furthermore, there is a need for tag devices capable of providing reliable information associated with a physical component such as the final mating position, serial number, model number, lot number, test report, test instruction, and maintenance record instruction, etc. One way of determining the connectivity of and/or the proper alignment of physical components is with an electronic identification system such as a radio-frequency identification (RFID) system. RFID systems can be used to identify, locate and track objects using wireless radio signaling in a reliable, accurate, real-time manner.